--- ray/src/rt/rayinit.cal	1995/08/25 11:43:29	2.9
+++ ray/src/rt/rayinit.cal	1996/02/29 11:13:34	2.10
@@ -101,7 +101,7 @@ noneg(v) = if(v,v,0);
 red(r,g,b) = if(r,r,0);
 green(r,g,b) = if(g,g,0);
 blue(r,g,b) = if(b,b,0);
-grey(r,g,b) = noneg(.263*r + .655*g + .082*b);
+grey(r,g,b) = noneg(.265074126*r + .670114631*g + .064811243*b);
 clip_r(r,g,b) = bound(0,r,1);
 clip_g(r,g,b) = bound(0,g,1);
 clip_b(r,g,b) = bound(0,b,1);